CTScans

Computed tomography (CT) scans are medical imaging tests that combine X-ray measurements taken from different angles with computer processing to produce cross-sectional images of the body. CT can reveal bone, soft tissue, and blood vessels with high detail and can be reconstructed into three-dimensional views.

A CT scanner uses an X-ray tube that rotates around the patient while detectors measure the transmitted radiation. The resulting data are compiled by a computer into axial slices and can be reformatted in multiple planes or as 3D images. Most CT studies use a contrast agent to improve tissue visibility; contrast may be given orally or intravenously. Modern scanners with multiple detector rows (multislice CT) provide rapid imaging with high resolution.

Common indications include evaluation after trauma, chest pain assessment, suspected pulmonary embolism or stroke, abdominal or pelvic pain, cancer detection and staging, and guidance for biopsies or minimally invasive procedures. CT angiography uses contrast to visualize blood vessels and is widely used in vascular assessments.

Safety and risks include exposure to ionizing radiation, which prompts efforts to minimize dose. Intravenous or oral contrast agents can cause allergic reactions and, rarely, kidney injury, especially in people with preexisting kidney disease. Pregnant patients require careful consideration due to fetal exposure. Preparation may involve fasting or hydration, depending on the study and use of contrast.

Limitations include lower soft-tissue contrast compared with MRI and susceptibility to artifacts from metal or patient motion. Alternatives such as magnetic resonance imaging or ultrasound may be used when appropriate. CT has a long history of development since the 1970s and remains a fast, widely available diagnostic tool.